SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd71f96eb90165c7caab9169572c3a07087d09cc93f85013d57914c6fced57221' 
  AND token = 'KaN3rF0FnH2sRS1YgMEsBUvrMTdHrO1p5QJB3ekarhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}